부산대학교 도서관

Obtained improvement in field of building stepped spillways-RCC method- has made stepped spillways and conditions of passing flow, problems that have attracted much attention of researchers. obtained result of experiments present that simultaneous installing deflector and aerator in first steps of spillway is one of effective tactics to increase passing discharge of spillway. stepped spillway and condition of flow passing it, have been considerable problems for researchers. In this study--according to limitation of water discharge per unit width passing stepped spillway--we not only examine amount of energy dissipation and dynamic pressure fluctuations on steps, but also seek a solution to shorten length of inception point of air entrance and increase pressure on steps. The results obtained of experiments show that simultaneous installing of deflector and aerator in upper part of spillway is one of the effective tactics to shorten black water length by pulling inception point to upper part of spillway. installing deflector has significant effect on energy dissipation and so shorten stilling basin. By installing aerator and enterance of air, pressure on the steps increases and cavitation risk decreases. Finally, by these finding, it is possible to increase water discharge passing spillway from q = 36 5 [m.sup.3]/s/m to q = 50 6 [m.sup.3]/s/m in milder slope (increasing 38.6%.) and from q = 30.9 [m.sup.3]/s/m to q = 401 m/s/m in steeper slope (increasing 29.3%). Key words: stepped spillway; deflector; energy dissipation; pressure fluctuation; cavitation index.
INTRODUCTION Increasingly growth of population, as well as improvement of technology are elements for loss of water in world and it causes about third of world population live with anxiety [...]